Management of common bile duct stones

Conclusions Choledocholithiasis remains a complicated and challenging disease process for today’s clinicians. Transabdominal ultrasound and ERC are the most common preoperative imaging modalities with endoscopic ultrasound, MRCP, and HCT emerging as potentially more accurate and less invasive tools. Intraoperatively, LUS and IOC are complimentary in detecting CBD stones, while laparoscopic CBDE is commonly and safely performed by surgeons comfortable with advanced laparoscopic techniques. Postoperative ERC is effective with failure of laparoscopic CBDE, surgeon inexperience, and unfavorable anatomy and patient selection. Open CBDE should never be looked upon as a failure, while sphincterotomy, sphincteroplasty, and choledochoenterostomy remain necessary operations for certain patients. The proposed algorithm is only a guideline, and ultimate treatment depends on physician experience and available resources.     

Endovascular treatment of iliac artery aneurysms with a tubular stent-graft: mid-term results

OBJECTIVE: To report the mid term results of a prospective cohort of iliac artery aneurysms (IAAs) treated with endovascular tubular stent-grafts. METHODS: All IAAs referred to the University Medical Center Groningen between June 1998 and June 2005 were evaluated for endovascular repair. Criteria for repair were a diameter of > or = 30 mm for anastomotic aneurysms and > or = 35 mm for true aneurysms. Preferentially, tubular grafts were used. Follow-up included both radiographs of the abdomen and duplex examination. RESULTS: In 35 patients, 40 IAAs were treated endovascularly with a tubular stent-graft. Elective repair was performed in 30 patients (86%) and emergent repair in five patients (14%). Aneurysms were false in 26 cases (65%) and true in 14 cases (35%). Local anesthesia was used in 74% of the cases. The stent-grafts that were used included the Excluder contralateral limb (n = 28, 70%), Passager (n = 9, 22.5%), Hemobahn (n = 2, 5%), and Wallgraft (n = 1, 2.5%). The mean operation time was 83 +/- 28 minutes (range, 50 to 150 minutes). Mean hospital stay was 3.3 +/- 2.3 days (range, 1 to 12 days). There was no 30-day mortality. Patients were followed up for a mean of 31.2 +/- 20.7 months (range, 3 to 83 months). Complications occurred in two patients during follow-up, including migration with a proximal type I endoleak in one, and occlusion of the stent-graft in the other. The internal iliac artery was intentionally sacrificed in 28 patients (70%), and this led to gluteal claudication in three patients. CONCLUSION: Endovascular repair of iliac artery aneurysms with flexible stent-grafts is a minimally invasive technique and is associated with low mortality and morbidity. Follow-up results up to 5 years suggest that the technique is durable. It should be regarded as a first choice treatment option for suitable aneurysms.     

Long-term viability and mechanical behavior following laser cartilage reshaping

OBJECTIVE: To investigate the long-term in vivo effect of laser dosimetry on rabbit septal cartilage integrity, viability, and mechanical behavior. METHODS: Nasal septal cartilage specimens (control and irradiated pairs) were harvested from 18 rabbits. Specimens were mechanically deformed and irradiated with an Nd:YAG laser across a broad dosimetry range (4-8 W and 6-16 seconds). Treated specimens and controls were autologously implanted into a subperichondrial auricular pocket. Specimens were harvested an average +/- SD of 208 +/- 35 days later. Tissue integrity, histology, chondrocyte viability, and mechanical property evaluations were performed. Tissue damage results were compared with Monte Carlo simulation models. RESULTS: All laser-irradiated specimens demonstrated variable tissue resorption and calcification, which increased with increased dosimetry. Elastic moduli of the specimens were significantly either lower or higher than controls (all P<.05). Viability assays illustrated a total loss of viable chondrocytes within the laser-irradiated zones in all treated specimens. Histologic examination confirmed these findings. Experimental results were consistent with damage profiles determined using numerical simulations. CONCLUSION: The loss of structural integrity and chondrocyte viability observed across a broad dosimetry range underscores the importance of spatially selective heating methods prior to initiating application in human subjects.     

The Effects of Retinoic Acid on the Insulin-like Growth Factor Axis in Primary Tissue Culture from Hyperparathyroidism

Background The importance of the IGF system in HPT has been previously demonstrated. Additionally, the role of vitamin A in HPT has been reported. Retinoic acid (RA), a derivative of vitamin A, is a ligand for the IGF II receptor (IGF2R). We have evaluated the interactions of RA with the IGF system in a primary parathyroid cell culture model. Materials and Methods Primary cell cultures were prepared from nine patients. Following adhesion, the cells were transferred to serum-free medium and dosed once with growth factors ± RA for 96 hours. Proliferation was assessed by measuring tritiated thymidine incorporation. Results Compared with the control group (100%), both IGF I and II increased DNA synthesis significantly. Retinoic acid significantly reduced the basal DNA synthesis to 82.2% ± 4.2% compared with control (P < 0.05). Retinoic acid ×10⁻⁵ M completely abrogated the proliferative actions of IGF II (70.2% ± 9.7%, P < 0.05) but had no significant effect on the IGF I response (P > 0.05). To evaluate the role of IGF2R or IGFBPs in mediating the actions of RA, the IGF II analogs [Leu27]IGF II (10–20-fold reduced IGF I receptor affinity) and des(1–6) IGF II (lower IGFBP binding affinity) were used. The IGF II inhibitory effect of RA was enhanced in the presence of analogs [Leu27]IGF II (P = 0.052) but not with des(1–6)IGF II (P > 0.05), compared with wild-type IGF II. Conclusions These data implicate a novel antiproliferative role for RA in enhancing the pericellular clearance of IGF II via the IGF2R preventing ligand activation of the IGF I receptor. This may have broader implications for RA effects in other tumors.     

The effects of neoadjuvant chemoradiation on pTNM staging and its prognostic significance in esophageal cancer

For esophageal cancer, it is not clear if pathologic TNM staging after chemoradiation and resection will have the same prognostic significance compared with patients who undergo resection only. From 1995 to 2004, prospectively collected data from 279 patients with intrathoracic squamous cell cancers were analyzed. Patients were given chemoradiation either as part of a randomized trial comparing neoadjuvant chemoradiation with surgical resection alone, or because of advanced disease at presentation. One hundred seventy patients had surgical resection only (surgery), and 109 had neoadjuvant chemoradiation (CRT plus surgery). In the surgery group, pT1, 2, 3, and 4 disease was found in 15, 17, 104, and 34 patients, respectively; their respective pN1 rates were 13.3%, 29.4%, 57.7%, and 64.7%, P<0.01. In CRT plus surgery, pT0, T1, 2, 3, and 4 were found in 48, 12, 23, 21, and 5 patients, respectively; their respective pN1 rates were 31.3%, 16.7%, 21.7%, 52.4%, and 20%, P=0.44. Logistic regression analysis of factors predictive of pN1 showed that pT stage correlated with pN1 status (P=0.005) in the surgery group, but not for the CRT plus surgery group. Cox regression analysis demonstrated that in the surgery group, pT, pN, and R category, and overall pTNM stage, were independent prognostic factors, whereas pN, R category, and gender were identified as relevant for CRT plus surgery. After chemoradiation, pT and overall pTNM stage groupings were not as clearly prognostic as in patients without prior therapy. Nodal status remains an important prognostic factor. Presented at the Forty-Seventh Annual Meeting of The Society for Surgery of the Alimentary Tract, Los Angeles, California, May 20–24, 2006 (oral presentation).     

Retrievable Inferior Vena Cava Filters: Initial Clinical Results

Anticoagulation is the accepted therapy for patients with thromboembolic disease. When contraindications to anticoagulant therapy are present, however, interruption of the inferior vena cava (IVC) may prevent pulmonary embolism (PE). The objective of this study was to report our early technical and clinical results with retrievable IVC filters (IVCFs) for the prevention of PE. One hundred and twenty-seven multitrauma patients between December 1, 2002, and December 31, 2004, underwent placement of Gunther-Tulip (n = 49), Recovery (n = 41), or OptEase (n = 37) retrievable IVCFs under real-time intravascular ultrasound (IVUS) guidance. All patients had abdominal X-rays to verify filter location. Prior to IVCF retrieval, all patients underwent femoral vein color flow ultrasonography to rule out deep vein thrombosis (DVT) and vena-cavography to assess the IVCF for trapped emboli, filter tilt, or retrained thrombus. Thirty-nine patients died of their injuries; no deaths were related to IVCF placement. One PE occurred during follow-up after filter retrieval, and two femoral vein insertion-site DVTs occurred. One hundred twenty (94.4%) of IVCFs were placed without complication at the L2-3 level, as verified by abdominal X-rays. Filter-related complications included three groin hematomas (2.9%) and three IVCFs misplaced in the right iliac vein early in our experience (2.3%); these filters were uneventfully retrieved and replaced in the IVC within 24 hr. Sixty-six patients underwent uneventful retrieval of IVCFs after DVT or PE anticoagulation prophylaxis was initiated. Forty-five IVCFs were not removed: 41 due to contraindications due to anticoagulation and four because of trapped thrombus within the filter. The role of retrievable IVCFs continues to evolve, but in this study of 127 patients, prophylactic temporary IVCF placement was simple and safe, prevented fatal PE, and served as an effective “bridge” to anticoagulation. Further investigation of this bedside IVUS technique and the role of temporary IVCFs in different patient populations is warranted. SECTION EDITOR: Samuel S. Ahn, MD     

Long-term survivorship analysis of cemented total hip replacement (THR) after avascular necrosis of the femoral head in renal transplant recipients.

BACKGROUND: We studied the long-term survival and the rate of revision of 93 consecutive total hip replacements (THRs) performed for avascular necrosis of the femoral head after renal transplantation from 1971 to 1988. Seventy-four were primary procedures while 19 hips had undergone previous surgery procedures on the same hip in the form of other conservative options. METHODS: The patients of mean age of 38 years were analysed by the Kaplan-Meier method with revision for any reason as the end-point. The follow-up period averaged 216 months (range 1-332). RESULTS: Thirteen hips were revised while 26 patients (36 hips) died during the follow-up period. The cumulative survival of the implant was 98.8% at 10 years and 63.8% at 20 years. CONCLUSIONS: Cemented THR performed after renal transplantation is satisfactory and, at least for the first 10 post-operative years, the results are equivalent to those obtained in the general population with primary osteoarthritis.     

Risk taking and tolerance of uncertainty: implications for surgeons

BACKGROUND: Adherence to evidence-based adverse outcome prevention techniques is a critical factor in providing high-quality patient care, but many of these interventions are not used by physicians. It is unclear if surgeons' risk attitudes and reactions to uncertainty influence their use of these or other interventions. MATERIALS AND METHODS: A systematic review of the literature was conducted to identify studies evaluating the effects of physicians' risk attitudes, reactions to uncertainty or ambiguity, and personality traits on clinical decision making. RESULTS: A variety of instruments to assess risk attitude and reactions to uncertainty have been developed and tested among physicians involved in critical care and emergency medicine. Scoring systems distinguish risk averse and risk seeking practitioners. In many studies, these characteristics were related to clinical decision making in situations of uncertainty. For example, among patients evaluated in the emergency room for chest pain, "risk-seeking" physicians admitted significantly fewer patients who did not have acute myocardial infarction than risk-avoiding physicians (29% and 47% of patients admitted, respectively). In contrast, risk-seeking physicians were no more likely to discharge a patient who eventually was found to have an acute myocardial infarction. CONCLUSIONS: There are very limited data on the extent to which surgical decision making is linked to risk taking behavior and "comfort with uncertainty". Understanding the behaviors, attitudes and beliefs that make up surgical "judgment" remains a challenge for those interested in influencing behavior.     

Donor‐specific chimeric antigen receptor Tregs limit rejection in naive but not sensitized allograft recipients

Cell therapy with autologous donor‐specific regulatory T cells (Tregs) is a promising strategy to minimize immunosuppression in transplant recipients. Chimeric antigen receptor (CAR) technology has recently been used successfully to generate donor‐specific Tregs and overcome the limitations of enrichment protocols based on repetitive stimulations with alloantigens. However, the ability of CAR‐Treg therapy to control alloreactivity in immunocompetent recipients is unknown. We first analyzed the effect of donor‐specific CAR Tregs on alloreactivity in naive, immunocompetent mice receiving skin allografts. Tregs expressing an irrelevant or anti‐HLA‐A2‐specific CAR were administered to Bl/6 mice at the time of transplanting an HLA‐A2⁺ Bl/6 skin graft. Donor‐specific CAR‐Tregs, but not irrelevant‐CAR Tregs, significantly delayed skin rejection and diminished donor‐specific antibodies (DSAs) and frequencies of DSA‐secreting B cells. Donor‐specific CAR‐Treg–treated mice also had a weaker recall DSA response, but normal responses to an irrelevant antigen, demonstrating antigen‐specific suppression. When donor‐specific CAR Tregs were tested in HLA‐A2‐sensitized mice, they were unable to delay allograft rejection or diminish DSAs. The finding that donor‐specific CAR‐Tregs restrain de novo but not memory alloreactivity has important implications for their use as an adoptive cell therapy in transplantation.     

Self-reported hypoglycaemia in insulin-treated patients with diabetes mellitus: results from the Singapore cohort of the International Operations Hypoglycaemia Assessment Tool study

INTRODUCTIONHypoglycaemia constitutes a significant barrier to achieving glycaemic control with insulin in both Type 1 (T1DM) and Type 2 diabetes mellitus (T2DM). The International Operations Hypoglycaemia Assessment Tool (IO HAT) study was designed to determine the incidence of hypoglycaemia in insulin-treated patients with T1DM and T2DM.METHODSThe IO HAT study retrospectively and prospectively assessed the incidence of hypoglycaemia in patients with insulin-treated diabetes mellitus in nine countries. This sub-analysis included patients from Singapore with T1DM or T2DM who were aged ≥ 21 years and had completed two self-assessment questionnaires (SAQ1 and SAQ2).RESULTSOf the 50 T1DM and 320 T2DM patients who completed the SAQ1, 39 T1DM and 265 T2DM patients completed SAQ2; 100% and 90.9%, respectively, experienced at least one hypoglycaemic event prospectively. The incidence rates of any hypoglycaemia were 49.5 events per patient-year (EPPY) and 16.1 EPPY for T1DM and T2DM patients, respectively, in the four-week prospective period. Hypoglycaemia rate did not differ in terms of glycated haemoglobin level. The vast majority of T1DM or T2DM patients (92.0% and 90.7%, respectively) knew the overall definition of hypoglycaemia before study participation, although over half of the patients (T1DM 54.0%, T2DM 51.9%) defined hypoglycaemia based only on symptoms.CONCLUSIONHigh proportions of insulin-treated patients with diabetes mellitus in Singapore reported hypoglycaemic events prospectively, showing that they had underreported hypoglycaemic episodes retrospectively. Patient education can help in improving hypoglycaemia awareness and its management in the region.